The jury in the trial of a young girl accused of stabbing two teachers and a fellow pupil at a school in South Wales has been discharged due to “irregularities”.

The 14-year-old, who cannot be named for legal reasons, admits wounding with intent but denied attempted murder after stabbing three people at Ysgol Dyffryn Aman – also known as Amman Valley School – in Ammanford, Carmarthenshire, on April 24.

During the trial at Swansea Crown Court on Wednesday, Judge Paul Thomas KC discharged the jury.

The trial was in its final stages at Swansea Crown Court (Tim Ireland/PA)

He said: “There has been a great irregularity in the jury which we all agree has irretrievably compromised our ability to consider this matter.

“With the greatest of possible reluctance, I will have to discharge this jury.”

The judge said the move was undesirable and the girl will have to stand trial again next year.

A new trial has been set for January 27.

One member of the jury was asked to stay behind and the public to leave the court.

The trial had been in its final stages, with the jury sent out to consider verdicts on Tuesday.

The teenager, who was 13 at the time of the incident, attacked teachers Fiona Elias and Liz Hopkin during the school’s morning break.

She then moved on to stab another girl before being restrained by staff.

All three victims survived the attack but Ms Hopkin, who was stabbed in the neck, had to be flown to Cardiff by air ambulance.